---
title: "CVE-2012-2459: Critical Vulnerability (denial-of-service)"
shorturl: "dos"
active: false
show_toc: true
banner: ""
date: 2012-05-14
---

<div class="post-content" markdown="1">
<h2 id="risks">Risks</h2>
<p>
A denial-of-service vulnerability that affects all versions of
bitcoind and Bitcoin-Qt has been reported and fixed. An attacker
could isolate a victim's node and cause the creation of blockchain
forks.
</p>
</div>

<div class="toccontent-block boxexpand expanded" markdown="1">
<h2 id="solutions">Solutions</h2>
<p>
Because this bug could be exploited to severely disrupt the Bitcoin
network we consider this a critical vulnerability, and encourage
everybody to upgrade to <a href="http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.6.2/">the latest version: 0.6.2</a>.
</p>
<p>
<a href="https://bitcointalk.org/?topic=79651">Backports for older releases (0.5.5 and 0.4.6) are also available</a> if
you cannot upgrade to version 0.6.2.
</p>
</div>

<div class="toccontent-block boxexpand expanded" markdown="1">
<h2 id="technical-details">Technical Details</h2>
<p>
Full technical details are being withheld to give people the
opportunity to upgrade.
</p>
<p>
Thanks to <a href="http://forre.st/">Forrest Voight</a> for discovering and reporting the vulnerability.
</p>
</div>

<div class="toccontent-block boxexpand expanded" markdown="1">
<h2 id="questions-and-answers">Questions &amp; Answers</h2>
<h3 id="how-do-i-know">
How would I know if I am the victim of this attack?
</h3>
<p>
Your bitcoin process would stop processing blocks and would have a
different block count from the rest of the network (you can see the
current block count at websites like <a href="http://blockexplorer.com/">blockexplorer.com</a> or
<a href="http://blockchain.info/">blockchain.info</a>).  Eventually it would display the message:
</p>
<blockquote>WARNING: Displayed transactions may not be correct!  You may need to
upgrade, or other nodes may need to upgrade.</blockquote>
<p>
(note that this message is displayed whenever your bitcoin process
detects that the rest of the network seems to have a different
block count, which can happen for several reasons unrelated to
this vulnerability).
</p>
<h3 id="can-my-wallet-be-stolen">
Could this bug be used to steal my wallet?
</h3>
<p>
No.
</p>
<h3 id="can-malware-be-installed">
Could this bug be used to install malware on my system?
</h3>
<p>
No.
</p>

<div style="text-align:right">
  <i>This notice last updated: Mon, 14 May 2012 17:00:00 UTC</i>
</div>
</div>
